108 
Psyche 
[December 
(especially in afranius) ; the upper lobe of the right valve 
is smaller, and its lower outer edge is not lobed and is more 
or less distinctly toothed ; the lower lobe is long and slender 
and toothed at the tip (the teeth weak or occasionally ab- 
Fig. 1. Each figure shows the left valve on left, tegumen in side 
view in the center, and right valve at right. 1, T. persius, Bristol, R. I. 
2, T. baptisise, type, Woods Hole, Mass.; 3, T. lucilius, Ithaca, N. Y.; 
4, T. afranius, Ariz.; 5, T. persius, type, Mass. 
